18084421 has 2 divisors, whose sum is σ = 18084422. Its totient is φ = 18084420.

The previous prime is 18084401. The next prime is 18084461. The reversal of 18084421 is 12448081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14516100 + 3568321 = 3810^2 + 1889^2 .

It is a cyclic number.

It is not a de Polignac number, because 18084421 - 2⁹ = 18083909 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18084421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18084401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9042210 + 9042211.

It is an arithmetic number, because the mean of its divisors is an integer number (9042211).

Almost surely, 2^18084421 is an apocalyptic number.

It is an amenable number.

18084421 is a deficient number, since it is larger than the sum of its proper divisors (1).

18084421 is an equidigital number, since it uses as much as digits as its factorization.

18084421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2048, while the sum is 28.

The square root of 18084421 is about 4252.5781591877. The cubic root of 18084421 is about 262.4832146485.

The spelling of 18084421 in words is "eighteen million, eighty-four thousand, four hundred twenty-one".